JPH06149033A - Developing device - Google Patents
Developing deviceInfo
- Publication number
- JPH06149033A JPH06149033A JP4316538A JP31653892A JPH06149033A JP H06149033 A JPH06149033 A JP H06149033A JP 4316538 A JP4316538 A JP 4316538A JP 31653892 A JP31653892 A JP 31653892A JP H06149033 A JPH06149033 A JP H06149033A
- Authority
- JP
- Japan
- Prior art keywords
- developer
- supply
- developing roller
- plate
- roller
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Landscapes
- Dry Development In Electrophotography (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、複写機、ファクシミ
リ、プリンター等の画像形成装置の現像装置に係り、詳
しくは、現像剤供給部材から現像剤担持体に現像剤を有
効に供給できる現像装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for an image forming apparatus such as a copying machine, a facsimile machine, a printer, etc., and more specifically, a developing device capable of effectively supplying a developer from a developer supplying member to a developer carrier. It is about.
【0002】[0002]
【従来の技術】従来、例えば、現像剤収容器内に設けら
れた搬送部材によって現像剤収容器内から搬送されてき
た現像剤を、現像器内に設けられた現像剤供給部材によ
って現像剤担持体に供給し、現像剤担持体に付着した現
像剤のうち余分な現像剤を現像剤規制部材によって掻き
取り、現像剤担持体上の現像剤を所定の厚さにした後、
この現像剤を潜像担持体表面に形成された潜像に対して
供給し現像を行う現像装置が知られている。また、上記
現像装置において現像剤担持体を例えば、回転可能な駆
動ローラと、この駆動ローラに外装され、駆動ローラの
周長よりもわずかに長い周長を有し、かつ、少なくとも
表面の一部が粗面化処理された無端のベルト状部材とに
より構成したものも知られている(例えば、特開平1−
257981号公報、特開平1−257982号公報参
照)。2. Description of the Related Art Conventionally, for example, a developer carried from a developer container by a carrying member provided in a developer container is carried by a developer supplying member provided in the developer container. After being supplied to the body and scraped off the excess developer of the developer adhered to the developer carrier by the developer regulating member, the developer on the developer carrier is made to have a predetermined thickness,
There is known a developing device that supplies the developer to the latent image formed on the surface of the latent image carrier to develop the latent image. Further, in the developing device, the developer carrying member is, for example, a rotatable drive roller, and has a peripheral length slightly longer than the peripheral length of the drive roller and is mounted on the drive roller, and at least a part of the surface. Is also known (for example, Japanese Unexamined Patent Publication No.
257981 and Japanese Patent Laid-Open No. 1-257982).
【0003】ここで、現像剤供給部材や現像剤担持体
は、現像剤収容器内から供給されてきた現像剤のうち、
それらの表面に形成された粗面部分に接触し担持された
現像剤を搬送するので、それほど多量の現像剤を搬送す
ることはできず、その現像剤搬送量には限界がある。従
って、搬送部材や現像剤供給部材や現像剤担持体の現像
剤搬送能力が一定条件の下で、例えば高濃度の現像が続
くと、最初の現像で現像剤担持体上の現像剤がほとんど
消費され、それ以降の現像においては現像剤担持体によ
る現像剤供給量(現像剤担持体上に保持された現像剤
量)が不足し、濃度低下を起こすことがあるという問題
点があった。Here, the developer supply member and the developer carrier are among the developers supplied from the developer container.
Since the developer carried in contact with the rough surface portion formed on those surfaces is carried, a large amount of developer cannot be carried, and the developer carrying amount is limited. Therefore, if the developer carrying ability of the carrying member, the developer supplying member, and the developer carrying body is constant, for example, if high-concentration development continues, the developer on the developer carrying body is almost consumed in the first development. However, in the subsequent development, there is a problem that the amount of developer supplied by the developer carrying member (the amount of developer held on the developer carrying member) becomes insufficient and the density may decrease.
【0004】そこで、この問題点を解決するために、現
像剤担持体に対してある程度の圧力を加えて現像剤を供
給することが提案されている。具体的には、現像剤供給
部材の上方に現像剤整流部材を固定して配設し、この現
像剤整流部材と現像剤供給部材とで現像剤流路を形成
し、現像剤収容器内から搬送されてきた現像剤が現像剤
流路を通過する際、現像剤整流部材によって現像剤に圧
力を加えて現像剤担持体に供給するように構成した現像
装置が提案されている(例えば、特開平4−57080
号公報参照)。Therefore, in order to solve this problem, it has been proposed to supply the developer by applying a certain pressure to the developer carrier. Specifically, a developer rectifying member is fixedly arranged above the developer supply member, and a developer flow path is formed by the developer rectifying member and the developer supply member, and from the inside of the developer container. A developing device has been proposed in which, when the conveyed developer passes through the developer flow path, the developer rectifying member applies pressure to the developer and supplies the developer to a developer carrier (for example, Kaihei 4-57080
(See Japanese Patent Publication).
【0005】[0005]
【発明が解決しようとする課題】ところが、上記特開平
4−57080号公報に示された現像装置における各部
材の配置や具体的形状によっては、現像剤整流部材によ
ってある程度の圧力が加えられた現像剤は、現像剤流路
出口付近で滞留しやすくなり、現像剤担持体の回転によ
る現像剤の流れが安定せず、その結果、現像剤担持体に
より潜像担持体に対して供給される現像剤量を一定に保
つことができないおそれがあることを確認した。また、
非現像時等の現像剤の流れがないときには、現像剤は現
像剤整流部材による圧力によってパッキングし、現像剤
流路で現像剤詰まりが発生するおそれがあることを確認
した。However, depending on the arrangement and the specific shape of each member in the developing device disclosed in Japanese Patent Laid-Open No. 4-57080, the developing process is performed by applying a certain amount of pressure by the developer rectifying member. The developer easily stays near the outlet of the developer flow path, the flow of the developer is not stable due to the rotation of the developer carrier, and as a result, the developer supplied to the latent image carrier by the developer carrier. It was confirmed that the dose could not be kept constant. Also,
It was confirmed that when there is no flow of the developer during non-development, the developer is packed by the pressure of the developer rectifying member, and the developer may be clogged in the developer flow path.
【0006】本発明は以上の問題点に鑑みなされたもの
であり、その第1の目的とするところは、現像剤に適当
な圧力を加えて現像剤担持体に供給した場合でも、現像
剤を現像剤流路出口付近で滞留させることなく、現像剤
担持体の回転による現像剤の流れを安定させることで、
現像剤担持体による潜像担持体に対する現像剤の供給量
を一定に保つことができる現像装置を提供することであ
る。また、第2の目的とするところは、上記第1の目的
に加えて現像剤流路での現像剤詰まり等の現像剤供給不
良を防止し、安定した良好な現像剤供給性能を得ること
ができる現像装置を提供することである。The present invention has been made in view of the above problems. A first object of the present invention is to supply a developer to a developer carrying member by applying an appropriate pressure to the developer. By stabilizing the flow of the developer due to the rotation of the developer carrier without allowing the developer to stay near the outlet of the developer channel,
It is an object of the present invention to provide a developing device capable of keeping the amount of developer supplied to the latent image carrier by the developer carrier constant. In addition to the first purpose, the second purpose is to prevent developer supply failure such as developer clogging in the developer flow path and to obtain stable and good developer supply performance. It is to provide a developing device capable of performing.
【0007】[0007]
【課題を解決するための手段】上記第1の目的を達成す
るために、請求項1の発明は、表面に潜像が形成された
潜像担持体に現像剤を供給する現像剤担持体と、該現像
剤担持体に現像剤を供給する現像剤供給部材と、該現像
剤供給部材に間隔をおいて対向して、該現像剤供給部材
との対向部に該現像剤担持体への現像剤流路を形成する
現像剤整流部材とを備えた現像装置において、該現像剤
担持体近傍における該現像剤整流部材の端部を、該現像
剤担持体との間で該現像剤担持体回転方向下流側に該現
像剤を導くように構成したことを特徴とするものであ
る。また、上記第2の目的を達成するために、請求項2
の発明は、請求項1の現像装置において、上記現像剤整
流部材を、非現像時には上記現像剤に対する押圧力を減
少させるように、上記現像剤供給部材から離れ得るよう
に構成したことを特徴とするものである。また、上記第
1の目的を達成するために、請求項3の発明は、請求項
1の現像装置において、上記現像剤整流部材の、少なく
とも上記現像剤担持体近傍部を導体で構成し、かつ、該
現像剤整流部材と該現像剤担持体と上記現像剤供給部材
とを所定の間隙を形成するように配置し、該現像剤整流
部材と該現像剤担持体との間と、該現像剤整流部材と該
現像剤供給部材との間の少なくとも一方に、周期的に少
なくとも強さが変わる電界を形成する電圧を印加したこ
とを特徴とするものである。In order to achieve the first object, the invention of claim 1 is a developer carrier for supplying a developer to a latent image carrier having a latent image formed on the surface thereof. , A developer supply member for supplying the developer to the developer carrier, and a developer supply member facing the developer supply member with a space therebetween, and developing on the developer carrier at a portion facing the developer supply member. In a developing device provided with a developer rectifying member that forms a developer flow path, an end portion of the developer rectifying member near the developer carrier is rotated between the developer carrier and the developer carrier. It is characterized in that the developer is guided to the downstream side in the direction. Further, in order to achieve the second object, the claim 2
The invention of claim 1 is characterized in that, in the developing device according to claim 1, the developer rectifying member can be separated from the developer supplying member so as to reduce the pressing force against the developer during non-developing. To do. Further, in order to achieve the first object, the invention of claim 3 is the developing device of claim 1, wherein at least the portion near the developer carrying member of the developer rectifying member is made of a conductor, and The developer rectifying member, the developer carrying member, and the developer supplying member are arranged so as to form a predetermined gap, and between the developer rectifying member and the developer carrying member, and the developer. A voltage is applied to at least one of the rectifying member and the developer supplying member to form an electric field whose intensity changes periodically at least.
【0008】[0008]
【作用】請求項1の発明においては、現像剤流路を通過
した現像剤は、現像剤担持体近傍における現像剤整流部
材の端部に沿って現像剤担持体回転方向下流側に導か
れ、現像剤担持体に供給される。請求項2の発明におい
ては、非現像時に現像剤流路に留まる現像剤は、現像剤
整流部材と現像剤供給部材とによる押圧状態から開放さ
れる。請求項3の発明においては、現像剤整流部材と現
像剤担持体との間と、現像剤整流部材と現像剤供給部材
との間の少なくとも一方に、周期的に少なくとも強さが
変わる電界が形成されるので、現像剤は、現像剤整流部
材と現像剤担持体との間あるいは現像剤整流部材と現像
剤供給部材との間の少なくとも一方で振動し、流動性が
高まる。According to the invention of claim 1, the developer having passed through the developer flow path is guided to the downstream side in the rotation direction of the developer carrying member along the end of the developer rectifying member in the vicinity of the developer carrying member, It is supplied to the developer carrier. In the invention of claim 2, the developer remaining in the developer flow path at the time of non-development is released from the pressed state by the developer rectifying member and the developer supply member. According to the third aspect of the invention, an electric field whose strength changes periodically is formed at least between the developer rectifying member and the developer carrier and between the developer rectifying member and the developer supplying member. Therefore, the developer vibrates at least one of between the developer rectifying member and the developer carrying member or between the developer rectifying member and the developer supplying member, and the fluidity is enhanced.
【0009】[0009]
【実施例】以下、本発明を画像形成装置である電子写真
複写機(以下、複写機という)に適用した一実施例につ
いて説明する。図1は本実施例に係る複写機に使用され
る現像装置の概略構成図である。この現像装置1におい
ては、開口部2に、潜像担持体としての感光体ドラム2
0表面に形成された潜像を現像するために、感光体ドラ
ム20に対向し回転可能に支持された現像剤担持体とし
ての現像ローラ3が設けられている。現像装置1のケー
シング底部には、現像ローラ3と所定の間隔をとって回
転可能に支持された、現像ローラ3に対して現像剤を供
給するための現像剤供給部材としての供給ローラ4が設
けられている。現像剤収容部5内には、軸61を中心に
回転可能に構成された、現像剤収容部5内に収容された
現像剤(図示せず)を供給ローラ4に対して補給するた
めのアジテータ6が設けられている。DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an electrophotographic copying machine (hereinafter referred to as a copying machine) which is an image forming apparatus will be described below. FIG. 1 is a schematic configuration diagram of a developing device used in a copying machine according to this embodiment. In the developing device 1, the photosensitive drum 2 as a latent image carrier is provided in the opening 2.
In order to develop the latent image formed on the 0 surface, a developing roller 3 is provided as a developer bearing member that faces the photosensitive drum 20 and is rotatably supported. At the bottom of the casing of the developing device 1, there is provided a supply roller 4 as a developer supply member for supplying a developer to the developing roller 3, which is rotatably supported at a predetermined distance from the developing roller 3. Has been. An agitator configured to be rotatable around a shaft 61 in the developer accommodating portion 5 for supplying the developer (not shown) accommodated in the developer accommodating portion 5 to the supply roller 4. 6 is provided.
【0010】また、図示の現像装置1においては、現像
ローラ3表面に付着した現像剤のうち余分な現像剤を掻
き落し、現像ローラ3表面に現像剤の薄層を形成すると
同時に、現像ローラ3に付着した現像剤を摩擦帯電させ
るための現像剤規制部材7が、設けられており、この現
像剤規制部材7と現像装置1の底部を形成するケーシン
グとで開口部2を形成している。Further, in the developing device 1 shown in the figure, excess developer of the developer adhering to the surface of the developing roller 3 is scraped off to form a thin layer of the developer on the surface of the developing roller 3, and at the same time, the developing roller 3 A developer regulating member 7 for frictionally charging the developer adhered to is provided, and the developer regulating member 7 and a casing forming the bottom of the developing device 1 form an opening 2.
【0011】そして、供給ローラ4の上方には、該供給
ローラ4と共に、アジテータ6により搬送された現像剤
の現像ローラ3への現像剤流路9を形成する現像剤整流
部材としての板状の整流板8が配設されている。図中こ
の整流板8は、その下面に平行な直線L1で示すよう
に、水平線L2に対して角度θ1を形成し、現像ローラ
3側端部(以下、先端部という)81がアジテータ6側
端部(以下、後端部という)82よりも下がった状態を
取るように配設されている。更に、この整流板8は先端
部81近傍の屈曲部83において、上方、すなわち現像
ローラ3回転方向下流側に屈曲しており、その下面に平
行な直線L3で示すように、上記直線L1に対して角度
θ2を形成し、先端部81が屈曲部83よりも上がった
状態を取るようにされている。以上の構成により、現像
剤流路9は概略、その現像剤入り口が広く開口し、屈曲
部83に近づくにつれて狭くなっており、屈曲部83か
ら現像剤出口に近づくにつれて再び広くなっていくよう
に形成されている。Above the supply roller 4, a plate-like member serving as a developer rectifying member that forms a developer flow path 9 for the developer conveyed by the agitator 6 to the developing roller 3 together with the supply roller 4. A current plate 8 is provided. As shown by a straight line L1 parallel to the lower surface of the straightening plate 8 in the drawing, an angle θ1 is formed with respect to the horizontal line L2, and the developing roller 3 side end portion (hereinafter, referred to as the leading end portion) 81 has an agitator 6 side end. It is arranged so as to be in a state of being lowered from a portion (hereinafter, referred to as a rear end portion) 82. Further, the straightening plate 8 is bent upward at the bent portion 83 near the tip 81, that is, on the downstream side in the rotation direction of the developing roller 3, and as shown by a straight line L3 parallel to the lower surface thereof, with respect to the straight line L1. To form an angle θ2 so that the tip 81 is raised above the bent portion 83. With the above-described configuration, the developer flow passage 9 generally has a wide opening at the developer inlet, becomes narrower as it approaches the bent portion 83, and becomes wider again as it approaches the developer outlet from the bent portion 83. Has been formed.
【0012】以上の構成において、現像剤は、アジテー
タ6が軸61を中心にして矢印方向に回転することで現
像剤収容部5から供給ローラ4方向へ搬送される。そし
て、現像剤は、整流板8と供給ローラ4とで形成される
現像剤流路9を通って現像ローラ3へ供給される。現像
ローラ3に供給され現像ローラ3表面に、例えば電気的
(あるいは磁気的、物理的)に付着した現像剤は、現像
ローラ3が矢印方向に回転することで、現像剤規制部材
7により現像ローラ3表面に所定の量を残して掻き取ら
れる。このとき、現像ローラ3表面に残った現像剤は、
現像剤規制部材7により摩擦帯電され、感光体ドラム2
0と現像ローラ3とが対向し現像が行われる現像領域に
おいて、感光体ドラム20表面に形成された潜像に付着
して、潜像を現像する。また、現像剤規制部材7を通過
できなかった現像剤は現像装置1内に戻り、上記動作が
繰り返される。In the above structure, the developer is conveyed from the developer accommodating portion 5 toward the supply roller 4 when the agitator 6 rotates about the shaft 61 in the arrow direction. Then, the developer is supplied to the developing roller 3 through a developer flow passage 9 formed by the flow straightening plate 8 and the supply roller 4. The developer supplied to the developing roller 3 and attached to the surface of the developing roller 3 electrically (or magnetically or physically), for example, is rotated by the developing roller 3 in the direction of the arrow so that the developer regulating member 7 causes the developing roller to rotate. 3 The surface is scraped, leaving a predetermined amount. At this time, the developer remaining on the surface of the developing roller 3 is
The photoconductor drum 2 is frictionally charged by the developer regulating member 7.
In the developing area where 0 and the developing roller 3 are opposed to each other and the developing is performed, the latent image is developed by adhering to the latent image formed on the surface of the photoconductor drum 20. Further, the developer that could not pass through the developer regulating member 7 returns to the inside of the developing device 1 and the above operation is repeated.
【0013】次に、現像ローラ3に対する現像剤の流れ
について説明する。アジテータ6により搬送されてきた
現像剤は、現像剤流路9を通過していくにしたがって、
整流板8によって上方から圧縮されながら現像ローラ3
方向に搬送される。そして、屈曲部83を通過した現像
剤は、現像剤流路9出口における整流板8に沿って現像
ローラ3回転方向下流側に導かれ、回転する現像ローラ
3の表面に付着していく。Next, the flow of the developer to the developing roller 3 will be described. As the developer conveyed by the agitator 6 passes through the developer flow path 9,
The developing roller 3 while being compressed from above by the current plate 8.
Is conveyed in the direction. Then, the developer that has passed through the bent portion 83 is guided to the downstream side in the rotation direction of the developing roller 3 along the straightening plate 8 at the outlet of the developer flow path 9 and adheres to the surface of the rotating developing roller 3.
【0014】また、本実施例においては、上記整流板8
は可動に構成されている。例えば、上記整流板8の後端
部82を回動自在に支持し、ソレノイド等のアクチュエ
ータを用いて先端部81側が上下動可能に構成されてい
る。そして、この整流板8は、現像時、すなわち現像剤
流路9を現像剤が流れている時には図2(a)に示す状
態にあり、現像剤流路9を通過する現像剤に対して適当
な圧力を加えている。また、この整流板8は、複写機の
動作が停止した時等の非現像時、すなわち現像剤流路9
中の現像剤が流れていない時には図2(b)に示すよう
に、図2(a)の状態に対して角度θ3を形成するよう
に後端部82を軸として先端部81側が上方に動き、現
像剤流路9や現像剤流路9出口近傍を広くして、現像剤
流路9中や現像剤流路9出口近傍に存在する現像剤に対
する圧力を弱くする。Further, in this embodiment, the straightening plate 8 is used.
Is movable. For example, the rear end portion 82 of the flow straightening plate 8 is rotatably supported, and the front end portion 81 side is vertically movable by using an actuator such as a solenoid. The current plate 8 is in the state shown in FIG. 2A during development, that is, when the developer is flowing through the developer flow path 9, and is suitable for the developer passing through the developer flow path 9. Applying a great pressure. Further, the current plate 8 is used for non-development such as when the operation of the copying machine is stopped, that is, the developer flow path 9
When the developer inside does not flow, as shown in FIG. 2B, the front end portion 81 side moves upward with the rear end portion 82 as an axis so as to form an angle θ3 with respect to the state of FIG. 2A. By widening the developer channel 9 and the vicinity of the outlet of the developer channel 9, the pressure on the developer existing in the developer channel 9 and in the vicinity of the outlet of the developer channel 9 is weakened.
【0015】以上の構成によれば、現像剤は、現像時に
は、整流板8によって適当な圧力が加えられても、現像
剤流路9出口近傍で現像剤が滞留することがなく、安定
した流れで現像ローラ3に供給され、また、非現像時に
は、現像剤流路9や現像剤流路9の現像剤出口近傍にお
いて現像剤詰まり(ブロッキング現象)を発生させるこ
とがない。According to the above structure, the developer does not stay near the outlet of the developer flow path 9 even if an appropriate pressure is applied by the straightening plate 8 during development, and the developer flows stably. Is supplied to the developing roller 3, and at the time of non-development, the developer channel 9 or the developer clogging (blocking phenomenon) in the vicinity of the developer outlet of the developer channel 9 does not occur.
【0016】なお、上記実施例に関する本発明者の実験
においては、現像ローラ3として、例えば、Alにサン
ドブラストをかけ表面粗さRzを5μm程度にしたも
の、又は表面にカーボンブラックや銅粒子を分散させた
アクリル系もしくはテフロン系もしくはSi系の樹脂を
10〜500μm程度塗布したものを用いた。また、供
給ローラ4として、例えば、発砲スポンジロール又は表
面を粗したAl又はSUS系の材質のものを用いた。ま
た、現像剤として、例えば、スチレンアクリル又はポリ
エステル混合のペレット抵抗1010Ωcm以上、比誘電
率4以下のものを用いた。第三添加剤としては、例え
ば、SiO2、TiO2、SiC又はステアリン酸亜鉛を
用い、これを0.1〜1.0wt%の間で母体と混合し
て用いた。特に、SiO2は粒径が80nm〜1μm程
度で、疎水性シリカを用いた。また、現像ローラ3と供
給ローラ4との間の間隙は、例えば、0.05〜1mmの
間に設定した。また、整流板8と、現像ローラ3あるい
は供給ローラ4との間の間隙は、例えば、最近接部にお
いては1mm以下に設定した。また、整流板8は、例え
ば、Al又はSUS板で、0.5mm以上の厚さに形成し
た。また、角度θ1,θ2,θ3は、例えば、角度θ1
を10〜30゜、角度θ2を20〜50゜、角度θ3を
10゜以上の範囲に設定した。また、供給ローラ4は、
現像ローラ3との対向領域において現像ローラ3の回転
方向(図1及び図2において反時計回り方向)に対する
つれ回り方向(図1及び図2において時計回り方向)に
回転させた。以上の条件で実験を行ったところ、現像ロ
ーラ3に対する現像剤の供給性能を良好に維持すること
ができた。In the experiments conducted by the present inventor in the above embodiments, the developing roller 3 is, for example, Al sandblasted to have a surface roughness Rz of about 5 μm, or carbon black or copper particles are dispersed on the surface. The acrylic resin, Teflon resin, or Si resin thus coated was used in an amount of about 10 to 500 μm. As the supply roller 4, for example, a foam sponge roll or a surface-roughened Al or SUS-based material is used. As the developer, for example, a mixture of styrene-acryl or polyester having a pellet resistance of 10 10 Ωcm or more and a relative dielectric constant of 4 or less was used. As the third additive, for example, SiO 2 , TiO 2 , SiC, or zinc stearate was used, and this was mixed with the base material in an amount of 0.1 to 1.0 wt%. In particular, SiO 2 has a particle size of about 80 nm to 1 μm and uses hydrophobic silica. Further, the gap between the developing roller 3 and the supply roller 4 is set to, for example, 0.05 to 1 mm. Further, the gap between the current plate 8 and the developing roller 3 or the supply roller 4 is set to, for example, 1 mm or less at the closest portion. The current plate 8 is, for example, an Al or SUS plate and is formed to have a thickness of 0.5 mm or more. Further, the angles θ1, θ2, and θ3 are, for example, the angle θ1.
Is set to 10 to 30 °, the angle θ2 is set to 20 to 50 °, and the angle θ3 is set to 10 ° or more. Further, the supply roller 4 is
In the area facing the developing roller 3, the developing roller 3 was rotated in the swirl direction (clockwise direction in FIGS. 1 and 2) with respect to the rotation direction (counterclockwise direction in FIGS. 1 and 2). When an experiment was conducted under the above conditions, the supply performance of the developer to the developing roller 3 could be maintained well.
【0017】次に、現像剤流路9中や現像剤流路9出口
近傍における現像剤を効率よく流動させるための実施例
について図3を参照しながら説明する。図3において、
現像ローラ3には直流成分を有する電圧(VR)が電源
30により印加されている。また、現像ローラ3に対し
て所定の間隙をとって配置された供給ローラ4にも直流
成分を有する電圧(VB)が電源31により印加されて
いる。また、現像ローラ3と供給ローラ4とに対して所
定の間隙をとって配置された整流板8には直流成分(V
S)と交流成分(VP-P)とを有する電圧が電源32によ
り印加されている。Next, an embodiment for efficiently flowing the developer in the developer channel 9 and in the vicinity of the outlet of the developer channel 9 will be described with reference to FIG. In FIG.
The developing roller 3 is applied by the voltage (V R) is a power supply 30 having a DC component. Further, the voltage (V B ) having a DC component is also applied by the power supply 31 to the supply roller 4 arranged with a predetermined gap with respect to the developing roller 3. The rectifying plate 8 arranged with a predetermined gap between the developing roller 3 and the supply roller 4 has a DC component (V
A voltage having an S ) and an AC component (V PP ) is applied by the power supply 32.
【0018】以上の構成において、整流板8と現像ロー
ラ3との間、及び整流板8と供給ローラ4との間には、
それぞれに印加された電圧により電界が形成される。そ
して、現像剤はこの電界によって静電気力を受ける。こ
こで、整流板8に印加された電圧は交流成分を有してい
るので、整流板8と現像ローラ3との間、及び整流板8
と供給ローラ4との間で形成される電界の少なくとも強
さが、上記交流成分により変化する。その結果、現像剤
は、整流板8と現像ローラ3との間、及び整流板8と供
給ローラ4との間を通過中に、上記交流成分により少な
くとも強さが変わる静電気力を受けて振動する。In the above structure, between the straightening plate 8 and the developing roller 3 and between the straightening plate 8 and the supply roller 4,
An electric field is formed by the voltage applied to each. Then, the developer receives an electrostatic force due to this electric field. Here, since the voltage applied to the rectifying plate 8 has an AC component, it is between the rectifying plate 8 and the developing roller 3 and between the rectifying plate 8 and the developing roller 3.
At least the strength of the electric field formed between the supply roller 4 and the supply roller 4 changes due to the AC component. As a result, the developer oscillates while being passed between the flow straightening plate 8 and the developing roller 3 and between the flow straightening plate 8 and the supply roller 4 by being subjected to an electrostatic force whose strength changes at least due to the AC component. .
【0019】以上、本実施例によれば、上記のように現
像ローラ3と供給ローラ4と整流板8とを所定の間隔を
とって配設し、整流板8と現像ローラ3との間、及び整
流板8と供給ローラ4との間の周期的に向きが変わる電
界によって、現像剤流路9中や現像剤流路9出口近傍に
おける現像剤を振動させることができるので、現像剤が
滞留することなく効率よく流動し、現像ローラ3に対す
る現像剤の供給を円滑に行うことができる。また、整流
板8と現像ローラ3との間、及び整流板8と供給ローラ
4との間で現像剤が振動するので、現像ローラ3や供給
ローラ4との間で現像剤が摩擦帯電され、その結果、現
像剤の帯電量を大きくすることができる。As described above, according to this embodiment, as described above, the developing roller 3, the supply roller 4, and the rectifying plate 8 are arranged at a predetermined interval, and between the rectifying plate 8 and the developing roller 3, Also, since the developer in the developer channel 9 or in the vicinity of the outlet of the developer channel 9 can be vibrated by the electric field that periodically changes the direction between the rectifying plate 8 and the supply roller 4, the developer stays. It is possible to efficiently flow without doing so and to smoothly supply the developer to the developing roller 3. Further, since the developer vibrates between the flow straightening plate 8 and the developing roller 3 and between the flow straightening plate 8 and the supply roller 4, the developer is frictionally charged between the developing roller 3 and the supply roller 4, As a result, the charge amount of the developer can be increased.
【0020】上記実施例に関する本発明者の実験におい
ては、上記図1及び図2に係る実施例に関する実験条件
に加えて、電源32の電圧として、例えば、整流板8と
現像ローラ3との間、及び整流板8と供給ローラ4との
間の電界として105〜107V/mの範囲の直流成分の
電圧(VS)と、下記数1に示す式を満足する交流成分
の電圧(VP-P)を用いた時、完全な現像剤の流動を確
認することができた。なお、下式のうち等号のない式を
満足する交流成分の電圧(VP-P)を用いた時には、交
流成分の周期に応じて電界の向きが変わって、整流板8
と現像ローラ3との間、及び整流板8と供給ローラ4と
の間での現像剤の往復運動を生じさせることにより、現
像剤の流動性をより一層高めることができた。In the experiments conducted by the inventor of the above embodiment, in addition to the experimental conditions relating to the embodiments of FIGS. 1 and 2, the voltage of the power supply 32 is, for example, between the straightening plate 8 and the developing roller 3. , And the voltage (V S ) of the DC component in the range of 10 5 to 10 7 V / m as the electric field between the rectifying plate 8 and the supply roller 4, and the voltage of the AC component (Equation 1) When VPP ) was used, complete developer flow could be confirmed. When the voltage (V PP ) of the AC component that satisfies the expression without the equal sign among the following formulas is used, the direction of the electric field changes according to the cycle of the AC component, and the rectifying plate 8
By causing the reciprocating motion of the developer between the developing roller 3 and the developing roller 3, and between the rectifying plate 8 and the supply roller 4, the fluidity of the developer can be further enhanced.
【数1】 [Equation 1]
【0021】また、本実施例においては、整流板8と現
像ローラ3の間や、整流板8と供給ローラ4の間に所定
の電界を形成するために、整流板8に交流成分を有する
電圧を印加したが、これに代え、整流板8と現像ローラ
3の間については現像ローラ3に交流成分を有する電圧
を印加し、また、整流板8と供給ローラ4の間について
は供給ローラ4に交流成分を有する電圧を印加してもよ
い。これらの場合、整流板8は、直流成分のみを有する
電圧が印加されるか、又は接地されていればよい。Further, in this embodiment, in order to form a predetermined electric field between the rectifying plate 8 and the developing roller 3 and between the rectifying plate 8 and the supply roller 4, a voltage having an AC component is applied to the rectifying plate 8. Instead of this, a voltage having an AC component is applied to the developing roller 3 between the rectifying plate 8 and the developing roller 3, and a voltage between the rectifying plate 8 and the supplying roller 4 is applied to the supplying roller 4. A voltage having an AC component may be applied. In these cases, the rectifying plate 8 may be applied with a voltage having only a DC component or may be grounded.
【0022】ところで、一般に現像ローラ3の軸方向両
端部においては、現像剤の消費が比較的少なく、この部
分に担持される現像剤は、長期間現像装置1内に留ま
り、現像剤同志や現像ローラ3表面等との摩擦により粉
砕で比較的小粒径化したり、その表面への添加物(第三
添加物)が埋没したりして、流動性や帯電性が低下して
いわゆるデッドトナーとなる。そして、このようなデッ
ドトナーは、現像ローラ3の軸方向両端部と整流板8と
の間隙に溜って(いわゆるブリッジ化)、現像剤供給不
良の原因となったり、感光体ドラム20表面に付着して
地汚れの原因となったりすることがあった。そこで、以
下では現像ローラ3の軸方向両端部に対応する整流板8
の両側端部での現像剤の滞留を防止するための実施例に
ついて説明する。図4(a)は現像ローラ3及び供給ロ
ーラ4近傍に配設された本実施例に係る整流板8aの説
明図であり、現像剤流路9入り口側から見たものであ
る。また、図4(b)は図4(a)中のX−X線矢印方
向の断面図である。整流板8aは、その側端部84が、
その下面に平行な直線L4で示すように、整流板8a下
面に平行な直線L5に対して角度θ4を形成するよう
に、屈曲部85において上方、すなわち現像ローラ3回
転方向下流側に屈曲している。以上の構成により、現像
剤流路9は、供給ローラ4(あるいは現像ローラ3)軸
方向両側が広くなるように形成されている。By the way, in general, the developer is consumed relatively little at both ends in the axial direction of the developing roller 3, and the developer carried in this portion stays in the developing device 1 for a long period of time, and the developer and the developing agent are in contact with each other. Due to friction with the surface of the roller 3 or the like, the particle size becomes relatively small by pulverization, and the additive (third additive) is buried in the surface, so that the fluidity and the charging property are deteriorated and a so-called dead toner is formed. Become. Then, such dead toner accumulates in the gap between the both ends of the developing roller 3 in the axial direction and the rectifying plate 8 (so-called bridge formation), which may cause developer supply failure or adhere to the surface of the photosensitive drum 20. Then, it may cause dirt. Therefore, in the following, the rectifying plates 8 corresponding to both axial end portions of the developing roller 3 will be described.
An example for preventing the retention of the developer at the both side end portions will be described. FIG. 4A is an explanatory view of the current plate 8a according to the present embodiment, which is arranged near the developing roller 3 and the supply roller 4, and is viewed from the inlet side of the developer flow path 9. 4 (b) is a sectional view taken along line XX in FIG. 4 (a). The rectifying plate 8a has a side end portion 84,
As indicated by a straight line L4 parallel to the lower surface thereof, it is bent upward at the bent portion 85, that is, to the downstream side in the rotation direction of the developing roller 3 so as to form an angle θ4 with respect to the straight line L5 parallel to the lower surface of the straightening plate 8a. There is. With the above configuration, the developer flow passage 9 is formed so that both sides in the axial direction of the supply roller 4 (or the developing roller 3) are wide.
【0023】以上の構成において、現像剤流路9を通過
する際に整流板8aによって上方から圧縮される現像剤
には、圧縮力の弱い整流板8aの側端部84側に向かう
流れが生じる。その結果、現像剤流路9幅方向(供給ロ
ーラ4(あるいは現像ローラ3)軸方向)における現像
剤の循環性が向上し、上記デッドトナーの発生を防止で
きるので、現像剤供給不良や地汚れを防止できる。ま
た、現像剤流路9幅方向に現像剤を一様に分布させるこ
とができるので、安定した現像剤供給を行うことができ
る。In the above structure, the developer compressed from above by the flow straightening plate 8a when passing through the developer flow path 9 has a flow toward the side end portion 84 side of the flow straightening plate 8a having a weak compression force. . As a result, the circulation of the developer in the width direction of the developer flow path 9 (the axial direction of the supply roller 4 (or the developing roller 3)) is improved, and the generation of the dead toner can be prevented. Can be prevented. Further, since the developer can be uniformly distributed in the width direction of the developer flow path 9, it is possible to stably supply the developer.
【0024】なお、上記実施例に関する本発明者の実験
によれば、角度θ4として、5°以上に設定することが
必要で、60°以下が好ましいという結果が得られた。According to the experiments conducted by the present inventor regarding the above-mentioned embodiment, the result that the angle θ4 needs to be set to 5 ° or more and is preferably 60 ° or less is obtained.
【0025】また、以上説明してきた実施例において、
現像ローラ3に対する現像剤供給量が追いつかない場
合、例えば、感光体線速が大きく現像剤供給量が足りな
い場合には、図5に示すような例えば断面形状が正方形
の回転体4aを現像剤供給部材として用いることができ
る。このような回転体4aを用いた場合、回転体4aが
回転すると、現像ローラ3や整流板8との間の距離が変
化するので、現像ローラ3に対する現像剤の搬送能力及
び圧接力を強くすることができ、安定した十分な現像剤
供給量を確保することができる。In the embodiment described above,
When the developer supply amount to the developing roller 3 cannot catch up, for example, when the photosensitive member linear velocity is high and the developer supply amount is insufficient, the rotating member 4a having a square cross-section as shown in FIG. It can be used as a supply member. When such a rotating body 4a is used, when the rotating body 4a rotates, the distance between the developing roller 3 and the rectifying plate 8 changes, so that the developer carrying ability and the pressure contact force with respect to the developing roller 3 are strengthened. It is possible to secure a stable and sufficient developer supply amount.
【0026】なお、上記実施例に関する本発明者の実験
によれば、回転体4aは一辺が5mm以上のもので、これ
を整流板8との最近接部の距離が300μm以下になる
ように配設し、回転体4aと現像ローラ3との周速比は
0.3以上で2以下が好ましく、回転体4aと現像ロー
ラ3との径(回転体4aが例えば断面正方形の場合は断
面における対角線長)の比は0.3以上あればよいとい
う結果が得られた。そして、以上の条件においては、感
光体ドラム20の線速が20〜180mm/sまで十分な
濃度の画像を得ることができた。According to an experiment conducted by the inventor of the above embodiment, one side of the rotating body 4a is 5 mm or more, and the rotating body 4a is arranged so that the distance of the closest portion to the current plate 8 is 300 μm or less. The peripheral speed ratio between the rotating body 4a and the developing roller 3 is preferably 0.3 or more and 2 or less, and the diameter of the rotating body 4a and the developing roller 3 (diagonal line in cross section when the rotating body 4a has a square cross section, for example). The result is that the ratio of (length) should be 0.3 or more. Under the above conditions, it was possible to obtain an image with sufficient density up to the linear velocity of the photosensitive drum 20 of 20 to 180 mm / s.
【0027】以上説明した実施例においては、先端部8
1が屈曲した整流板8を用いていたが、これに代えて図
6に示すような先端部81から後端部82まで屈曲して
いない整流板8bを用いることもできる。この場合、整
流板8bは、その下面に平行な直線L6で示すように、
現像ローラ3の中心点40と整流板8bの現像ローラ3
表面に対する最接近部811とを結ぶ直線L7に対して
角度θ5を形成するように配設することで、上記実施例
同様の効果を得ることができる。なお、この場合にはア
ジテータ6からの現像剤が効率よく現像剤流路9に流れ
るようにするために、アジテータ6を図示の位置よりも
若干下方に配設することが好ましい。In the embodiment described above, the tip portion 8
Although the straightening plate 8 of FIG. 1 is used, a straightening plate 8b that is not bent from the front end 81 to the rear end 82 as shown in FIG. 6 may be used instead. In this case, the rectifying plate 8b is, as indicated by a straight line L6 parallel to the lower surface thereof,
The center point 40 of the developing roller 3 and the developing roller 3 of the rectifying plate 8b
By arranging so as to form an angle θ5 with respect to the straight line L7 connecting the closest portion 811 to the surface, the same effect as in the above embodiment can be obtained. In this case, in order to allow the developer from the agitator 6 to efficiently flow into the developer flow path 9, it is preferable to dispose the agitator 6 slightly below the illustrated position.
【0028】[0028]
【発明の効果】請求項1の発明によれば、現像剤流路を
通過した現像剤は、現像剤担持体近傍における現像剤整
流部材の端部に沿って現像剤担持体回転方向下流側に導
かれ、現像剤担持体に供給されるので、現像剤整流部材
によって現像剤に適当な圧力を加えて現像剤担持体に供
給した場合でも、現像剤を現像剤流路出口付近で滞留せ
ず、現像剤担持体の回転による現像剤の流れが安定し、
その結果、現像剤担持体による潜像担持体に対する現像
剤の供給量を一定に保つことができ、安定した良好な現
像剤供給性能を得ることができるという効果がある。請
求項2の発明によれば、非現像時に現像剤流路に留まる
現像剤は、現像剤整流部材と現像剤供給部材とによる押
圧状態から開放されるので、現像時等の現像剤に対して
適当な圧力を加える必要があるときだけ所望の特性を得
ることができ、非現像時には、現像剤流路や現像剤流路
の現像剤出口近傍において現像剤詰まりを発生させるこ
とがないという効果がある。請求項3の発明によれば、
現像剤整流部材と現像剤担持体との間と、現像剤整流部
材と現像剤供給部材との間の少なくとも一方に、周期的
に少なくとも強さが変わる電界が形成されるので、現像
剤は、現像剤整流部材と現像剤担持体との間あるいは現
像剤整流部材と現像剤供給部材との間の少なくとも一方
で振動して流動性が高まる。このため、現像剤流路で現
像剤を滞留させることなく効率よく流動させることがで
き、現像剤担持体に対する現像剤の供給を円滑に行うこ
とができるという効果がある。また、現像剤担持体や現
像剤供給部材との間で現像剤が摩擦帯電され、その結
果、現像剤の帯電量を大きくすることができ、良好な画
像を得ることができるという効果がある。According to the first aspect of the invention, the developer having passed through the developer flow path is located downstream of the developer carrying member in the rotation direction along the end of the developer rectifying member in the vicinity of the developer carrying member. Since it is guided and supplied to the developer carrying member, the developer does not stay in the vicinity of the developer flow path outlet even when the developer rectifying member applies an appropriate pressure to the developer to supply it to the developer carrying member. , The flow of the developer is stabilized by the rotation of the developer carrier,
As a result, the amount of developer supplied to the latent image carrier by the developer carrier can be kept constant, and stable and good developer supply performance can be obtained. According to the second aspect of the present invention, the developer remaining in the developer flow path at the time of non-development is released from the pressing state by the developer rectifying member and the developer supply member. The desired characteristics can be obtained only when it is necessary to apply an appropriate pressure, and the effect of not causing developer clogging in the developer channel or near the developer outlet of the developer channel during non-development is obtained. is there. According to the invention of claim 3,
Since an electric field whose strength changes at least periodically is formed between at least one of the developer rectifying member and the developer carrying member and between the developer rectifying member and the developer supplying member, the developer is At least one of the developer rectifying member and the developer carrying member or the developer rectifying member and the developer supplying member vibrates to increase fluidity. Therefore, there is an effect that the developer can be efficiently flowed without staying in the developer flow path, and the developer can be smoothly supplied to the developer carrier. Further, the developer is triboelectrically charged between the developer carrier and the developer supplying member, and as a result, the amount of charge of the developer can be increased, and a good image can be obtained.
【図1】実施例に係る電子写真複写機に使用される現像
装置の概略構成図。FIG. 1 is a schematic configuration diagram of a developing device used in an electrophotographic copying machine according to an embodiment.
【図2】(a)は整流板を可動に構成した場合の、現像
剤流路を現像剤が流れている時の整流板の状態を示す説
明図。(b)は整流板を可動に構成した場合の、現像剤
流路を現像剤が流れていない時の整流板の状態を示す説
明図。FIG. 2A is an explanatory diagram showing a state of the flow straightening plate when the developer flows in the developer flow path when the flow straightening plate is configured to be movable. FIG. 6B is an explanatory diagram showing a state of the straightening vane when the developer is not flowing in the developer flow path when the straightening vane is configured to be movable.
【図3】現像ローラと供給ローラと整流板との間で現像
剤を振動させる例の概略構成図。FIG. 3 is a schematic configuration diagram of an example in which a developer is vibrated among a developing roller, a supply roller, and a rectifying plate.
【図4】(a)は他の実施例に係る整流板の説明図。
(b)は(a)中のX−X線矢印方向の断面図。FIG. 4A is an explanatory diagram of a current plate according to another embodiment.
(B) is sectional drawing of the XX line arrow direction in (a).
【図5】他の実施例に係る供給ローラの説明図。FIG. 5 is an explanatory diagram of a supply roller according to another embodiment.
【図6】他の実施例に係る整流板の説明図。FIG. 6 is an explanatory view of a current plate according to another embodiment.
3 現像ローラ 4 供給ローラ 8 整流板 81 先端部 82 後端部 83 屈曲部 9 現像剤流路 30 現像ローラ側電源 31 供給ローラ側電源 32 整流板側電源 3 Developing Roller 4 Supply Roller 8 Straightening Plate 81 Front End 82 Rear End 83 Bend 9 Developer Channel 30 Developing Roller Power Supply 31 Supplying Roller Power Supply 32 Rectifying Plate Power Supply
Claims (3)
剤を供給する現像剤担持体と、該現像剤担持体に現像剤
を供給する現像剤供給部材と、該現像剤供給部材に間隔
をおいて対向して、該現像剤供給部材との対向部に該現
像剤担持体への現像剤流路を形成する現像剤整流部材と
を備えた現像装置において、 該現像剤担持体近傍における該現像剤整流部材の端部
を、該現像剤担持体との間で該現像剤担持体回転方向下
流側に該現像剤を導くように構成したことを特徴とする
現像装置。1. A developer carrier for supplying a developer to a latent image carrier on the surface of which a latent image is formed, a developer supply member for supplying a developer to the developer carrier, and the developer supply. A developer carrying device, comprising: a developer rectifying member that forms a developer flow path to the developer carrier at a portion facing the developer supply member and is opposed to the member at a distance. A developing device, characterized in that an end portion of the developer rectifying member in the vicinity of the body is configured to guide the developer to the downstream side in the rotation direction of the developer carrying body with the developer carrying body.
現像剤に対する押圧力を減少させるように、上記現像剤
供給部材から離れ得るように構成したことを特徴とする
請求項1の現像装置。2. The developing device according to claim 1, wherein the developer rectifying member is configured so as to be separated from the developer supplying member so as to reduce the pressing force against the developer when not developing. .
像剤担持体近傍部を導体で構成し、かつ、該現像剤整流
部材と該現像剤担持体と上記現像剤供給部材とを所定の
間隙を形成するように配置し、該現像剤整流部材と該現
像剤担持体との間と、該現像剤整流部材と該現像剤供給
部材との間の少なくとも一方に、周期的に少なくとも強
さが変わる電界を形成する電圧を印加したことを特徴と
する請求項1の現像装置。3. A developer rectifying member, at least a portion in the vicinity of the developer carrying member is made of a conductor, and a predetermined gap is provided between the developer rectifying member, the developer carrying member and the developer supplying member. And at least one of the developer rectifying member and the developer carrying member, and at least one of the developer rectifying member and the developer supplying member have a cyclical strength. The developing device according to claim 1, wherein a voltage that forms a changing electric field is applied.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4316538A JPH06149033A (en) | 1992-10-30 | 1992-10-30 | Developing device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4316538A JPH06149033A (en) | 1992-10-30 | 1992-10-30 | Developing device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH06149033A true JPH06149033A (en) | 1994-05-27 |
Family
ID=18078224
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP4316538A Withdrawn JPH06149033A (en) | 1992-10-30 | 1992-10-30 | Developing device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH06149033A (en) |
-
1992
- 1992-10-30 JP JP4316538A patent/JPH06149033A/en not_active Withdrawn
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20000104 |